Generalized jordan curve theorem

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SUMMARY

The discussion centers on the proof of the generalized Jordan curve theorem using homology, specifically referencing Hatcher's algebraic topology book. The theorem asserts that a subspace of Sn homeomorphic to S(n-1) divides Sn into two components. The user inquires about extending this proof to general (n-1)-manifolds, noting that while the complement of an n-1-sphere in Sn has the homology of S0, this property does not hold for all n-1-manifolds. The user seeks insights on utilizing Alexander duality and the Mayer-Vietoris sequence to address challenges in their proof.

PREREQUISITES
  • Understanding of homology and cohomology concepts
  • Familiarity with the generalized Jordan curve theorem
  • Knowledge of the Mayer-Vietoris sequence
  • Basic principles of Alexander duality
NEXT STEPS
  • Study Hatcher's algebraic topology, particularly pages 169 and 254
  • Research the application of Alexander duality in topology
  • Explore the implications of the Mayer-Vietoris sequence in homological algebra
  • Investigate the properties of (n-1)-manifolds in relation to Sn
USEFUL FOR

Mathematicians, particularly those specializing in algebraic topology, graduate students studying topology, and researchers interested in manifold theory and homological methods.

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Is anyone here familiar with the proof (using homology) of the generalized Jordan curve theorem, that a subspace of S^n homeomorphic to S^(n-1) divides it into two components? It can be found on page 169 of Hatcher's algebraic topology book, which can be downloaded from http://www.math.cornell.edu/~hatcher/AT/ATpage.html" page.

I'm wondering if it's possible to use the same kind of proof to show that a general (n-1)-manifold divides S^n into two components. It was shown that the complement of an n-1-sphere in S^n actually has the homology of S^0, which is much stronger, and won't hold for general n-1-manifolds. But all I need is that the 0th reduced homology group is Z, which does seem to be true. The problem is that the corresponding terms of the Mayer-vietoris sequence used in Hatcher's proof aren't zero where they need to be. Does anyone have any ideas?
 
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are you using alexander duality? see p.254.
 
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I haven't gotten to that yet (Im just starting cohomology), though I see how it would follow from there. Is there an easier method, or a way to extract that bit of information using the idea of alexander duality without developing all the machinery?
 

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